Elliptic spring.



H. JEFFREY. ELLIPTIG SPRING.

APPLICATION FILED'JULY 12, 1909.

I Patented Nov. 30, 1909.

-5 T v i it T 0 all whom it may concern: 4

Be it known that l, .lillARRY JEFFREY, a citizen of the United States, residing at Louisville, in the county oi? Jefferson and State of Kentncky,.haye invented :2 new and useful lnqn'oveinent inEliipt-ic Springs, of which the following a specifics. on.

This invention relates to ellipticvehicle s 'n'ings, and especially to sorings for railroad cars," and the objects of n'ly improve inent are, strength and tlnraljiility,ease oi. manufacture, eheapness of nnmuhctttrr-x, flexibility, to provide a spring in which. the stillness and strength increases proportion atcly to the pressure upon it, and to avoid friction between the parts. These objects I attain by means of the structure illustrated. in the accompanying drawings, in WlllUll' Figure l is.a plan View; Fig. 2, .n sitlc ele' vation; Fig. 3, a side view of the adjacent; tin'iglainentol leaves under stress; and, Fig. =4- is a plan view of two spring elements joineil together.

Similar reference numerals refer to siinilar parts throughout the several views of the drawings.

The full elliptic spring co nprises the usual upper and lower sections 1 and My invention inheres in the peculiar construction of the adjacent fundamental lea ves 3 and l. The sn. pleinental leaves, are of the ordinary construction. The lea. of the npper and. lower sections of the sp ingj; are shown bound together by metal straps, (3 and lare hal'l -zinil-lialvcol together at their entl the blanks oil which they are fornieil being correspondingly notched, at one end on the right hand side, and at the other on the left hantl siile, as indicated by the reference nometals 3 and l in Fig. 1.. This I prefer to accomplisl'i when SllP-lll'il'l Q "llifi blanks from the bar of stock by Z-ihaqnctl cut. 'llhus there is no waste oi? material. The halt-hair extensions at. the ends the blank are then formed into syn'rnietrical anal similar eyes, 8

and 9. Roll fundamental leaves 3 not}, 4. are l Ul'ItH-Nl alike, and are therefore interchangeable. This resultsin an advantage both in the iminufnctnrc and in melting" repairs. I

- The leaves 3 anzl are made, at their entls.

l0 and. ll. interi'nerliate the eyes and the strap (3 or "'2', in. the form of on ogee curve, so that when two leaves are placed together mutually inc-n12. their atlgacent snri'aces bear T, the two fundamental leaves 3 and ore pieced through the eyes 8 and 9. Lpmstlo not lit the eyes snngz'h against each other er width, at 12- antl l3, nsr inward. of each eye. By reasoi'i of this construction, l1" 3; the leaves 3 and 4, ion COIN)??? in OlDEHb tion, hear again: other ni rolling contact, and, the the st, and consequent. compre sion, the more as contacts at the opposite owls e nronch each ot er and the-middle oil the so ng, and the stiller and stronger the spring heconie--1. 'lhe stiffness and strength of the sprii'ig, ilwrei orc, in creases in proportion to the pressure upon it.

The eyes 8 and 9 need not be accurately forinetl, since they are not required to have a. bearing upon one another or noon at pin or bolt, as is usual. A i

The leaves 3 and l are held in alineinent vertically by means of pins, l4- ainl 15, which These y, but very loosely, being of considerably less diameter than the bore of the eyt 'li'hey are adaptor] to secure the :tnntlai'nental leaves together laterally, and to allow the eyes to nzove freely vertically in opposite directlons relative to each other will; considerable amplitude. This movement is noc ssary on account; of the rolling contact (Fig. between the adjacent. leaves 3 and. It the eyes 8 and 9 and pins 14; and 15 made a snug bearing the eyes would be hrolten oil when. the spring was compressed.

in practice, I prefer to place two or more springs side by side, passing the bolts 14- and 15 through theeyes of the series, and thus joining theseveral elements together.

The second lent, l6, oil-each. section of the spring preferably square on the ends, anclbrought down to the outer surface of the eyes, shown at I? and 18.

moving tins thsorihetl my invei'ition, so that any one sltil rl in the art. oertnining thereto may make it and. unclerstahd its use, I claiin It. in on elliptic spring, having adjacent intercolmectirig leaves provided with an eye atc .1 end, the eyes of opposite Corie soonrhng leaves mutually half-entl-hzilved together laterally, said leaves joined to gether' by a pin adapted to holol them to gether laterally only, when the spring is under stress, soitl eyes being of larger (lienieter than said pin end. said pin being of smaller (liaxneter than said eyes, said leaves bearing against each. other interrne tliitte so. .yes and the initltlle of t-lz-espring,

irely' across their in such amanner that said leaves in operation bear against each other with a rolling contact.

2. In an elliptic spring, the adjacent fundamental leaves formed at their opposite ends with an ogee curve, the 'ogee curved portions being oppositely disposed so as to bear against each other in operation with a rolling contact.

3. In an elliptic spring, adjacent 'fundamental leaves, provided with eyes which are mutually laterall half-a'nd-halved together and secured toget er by means of pins which act laterally only, said eyes being free to move vertically in opposite directions mutually,

and said leaves bearing in operation with a rolling contact. 1

4. In a full elliptic spring, adjacent fundamental leaves secured together mutually in vertical alinement, adapted to bear against each other in operation with free rolling contact and nearer the middle of the spring as the stress is increased, so that the stiffness of the spring is increased as the pressure thereon is increased.

HARRY JEFFREY. 

